VDB-247880 · CVE-2023-6377 · RHSA-2023:7886

X.org X11 Server up to 21.1.9 XKB Button Action out-of-bounds write

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.7	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as critical has been found in X.org X11 Server. The affected element is an unknown function of the component XKB Button Action Handler. Such manipulation leads to out-of-bounds write. This vulnerability is referenced as CVE-2023-6377. The attack can only be performed from a local environment. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, has been found in X.org X11 Server (Windowing System Software). Affected by this issue is an unknown part of the component XKB Button Action Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A flaw was found in xorg-server. Querying or changing XKB button actions such as moving from a touchpad to a mouse can result in out-of-bounds memory reads and writes. This may allow local privilege escalation or possible remote code execution in cases where X11 forwarding is involved.

The weakness was published 12/13/2023. The advisory is shared for download at access.redhat.com. This vulnerability is handled as CVE-2023-6377 since 11/29/2023. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 211567 (Oracle Linux 9 : xorg-x11-server-Xwayland (ELSA-2024-9093)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 21.1.10 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (211567) and EUVD (EUVD-2023-58618). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Windowing System Software

Vendor

X.org

Name

X11 Server

Version

License

open-source

Website

Vendor: https://www.x.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.7

VulDB Base Score: 7.8
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CNA Base Score: 7.8
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 211567
Nessus Name: Oracle Linux 9 : xorg-x11-server-Xwayland (ELSA-2024-9093)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: X11 Server 21.1.10
Patch: gitlab.freedesktop.org

Timelineinfo

11/29/2023 🔍
12/13/2023 +14 days 🔍
12/13/2023 +0 days 🔍
07/09/2025 +574 days 🔍

Sourcesinfo

Vendor: x.org

Advisory: RHSA-2023:7886
Status: Confirmed

CVE: CVE-2023-6377 (🔍)
GCVE (CVE): GCVE-0-2023-6377
GCVE (VulDB): GCVE-100-247880
EUVD: 🔍

Entryinfo

Created: 12/13/2023 08:08
Updated: 07/09/2025 13:09
Changes: 12/13/2023 08:08 (49), 01/07/2024 02:53 (2), 01/07/2024 03:01 (1), 09/17/2024 00:14 (27), 11/19/2024 23:13 (2), 07/09/2025 13:09 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.